Control unit for bulk tank washers and the like



y 0, 1969 w. M. BOOTH ET AL 3,445,038

CONTROL UNIT FOR BULK TANK WASHERS AND THE LIKE Filed March 22, 1967 Sheet of s AJ/ALAOM ,edaaer A! elm/me 6563 4 waewas BY M M M Murray INVENTOR? May 20, 1969 w. M. BOOTH ET AL CONTROL UNIT FOR BULK TANK WASHERS AND THE LIKE Filed March 22, 1967 Sheet 2 of s emer M Pauoee W65 1/. 04.421494! BY Id/44V A ow/23441 United States Patent Ofiice 3,445,038 Patented May 20, 1969 US. Cl. 222-56 20 Claims ABSTRACT OF THE DISCLOSURE The control unit of the invention has a cabinet or housing defining an internal reservior for holding a predetermined quantity of water fed thereinto from a source through a solenoid-actuated valve means. A pump is provided for supplying liquid from the reservoir to an outlet, and the reservoir has a return, such that the outlet and the return may be connected to a bulk tank or the like and liquid from the reservoir circulated to and from such a tank. Dispensing units are provided for holding desired cleaning and/or sterilizing agents, and the operation of these dispensers is controlled by solenoids actuated by command signals from a timer or programmer, by which the contents of the dispensers are released through hoses or conduits into the aforesaid reservoir, to be dissolved in the liquid contained therein. The contents of the dispensers are carried into the reservoir by water under pressure from the pump, which flushes the agents out of the dispensers. A solenoid-actuated dump valve controlled 'by the aforesaid timer is provided for emptying the reservoir, and the timer is programmed such that previously-used Water is emptied from the reservoir and replaced with fresh water before either of the dispensers is operated. A predetermined quantity of liquid is maintained in the reservoir at all times by sensing means which detect the level of the liquid therein and provide control signals causing added water from the source to be admitted if the level in the reservoir decreases beyond the predetermined Background of the invention This invention relates primarily to means for washing the interior of liquid bulk storage tanks, such as are used for storing milk. More particularly, the invention relates to a control unit for supplying sequenced cleaning solutions and circulating such solutions to and from an external object to be cleaned, such as a bulk storage tank.

In copending application Ser. No. 563,810 entitled Bulk Tank Washing Apparatus, one of the present joint inventors has disclosed and claimed a novel structure comprising a spray means which is combined with a typical agitator and permanently mounted in the interior of a bulk storage tank. The present invention provides a source apparatus particularly well adapted for use with such a spray means, by which a desired sequence of different types of washing solutions are supplied to such a spray means and removed from the tank in a circulating operation.

Previously, the predominant method of cleaning such bulk tanks was a manual operation in which the tank was scrubbed internally with a brush or the like, using any of a variety of cleaning solutions. In some cases the agitator in the bulk tank was particularly adapted to splash cleaning solution contained therein throughout the interior thereof; in this operation a gearing change typically had to be provided so that the speed of the agitator was increased very substantially during the cleaning operation,

inasmuch as the speed required for merely stirring liquids stored in the tank is rather slow, whereas the speed required for cleaning by splashing is quite high.

Some spray-type cleaners for such tanks have been provided in the past, but neither these systems nor the other cleaning systems just noted included a suitable automated control unit for providing sequential cycles of different cleaning and sanitizing solutions which are continuously circulated through the bulk tank and the control unit, such as forms the subject matter of the present invention. Typically, the Water for the cleaning solutions in previous systems was supplied to the bulk tank or to the spray means mounted therein by merely using a hose connected to a conventional Water source, in a basically manual operation which relys entirely on the water pressure of the source for proper cleaning operation and which has proven to frequently overtax the typical private water supply on farms and the like where such tanks are primarily used. The cleaning agents themselves in such systems were supplied to the water from the source mainly by manually dumping the agents into the tank, or otherwise through a very elementary venturi system in which the flowing water drew the agents out of some sort of receptacle; also, the cleaning solutions themselves were typically drained and discarded directly from the tank, thereby wasting large amounts of water and cleaning materials.

Summary of the invention In contrast to the types of devices used previously, the present invention provides a programmed source of different washing liquids supplied in a predetermined sequence. The unit has plural dispenser means for holding different types of cleaning and/or sanitizing agents, and these agents are released into an internal reservoir upon a command signal from a timer which controls all functions of the unit to provide the desired sequence. This reservoir is filled from a source of water, and a predetermined quantity of liquid is maintained in the reservoir by means which sense the level of liquid therein and provide a signal to a control valve if additional water is required. This provides a significant advantage, in that during washing cycles wherein a hot solution is used, hot Water may be used exclusively to replenish the reservoir, thereby greatly helping to maintain the temperature of the solution being used. Liquid from the reservoir is supplied to the washing apparatus itself by a pump, and the liquid is continuously circulated between the bulk tank and the reservoir during any particular cycle of the washing sequence. This also has significant benefits, since the washing solution remains in contact with the refrigerated tank a much shorter time and therefore is subject to much less cooling. Also, the reservoir is automatically emptied before any of the dispensers is actuated, so that the water used in each cleaning cycle is fresh and contains only the cleaning agent from a single dispenser means. While the particular sequence of washing cycles is determined by the programming of the timer and is generally fixed, the timer may be reset to provide only an abbreviated portion of the total washing sequence, during which only a single one of the dispensers is operated, as for example when such dispenser contains a sanitizing acid and it is desired only to sanitize the tank without completely Washing its interior.

Drawings FIG. 1 is a frontal perspective view of the control unit of the invention, with the top of the cabinet being removed to show internal portions thereof;

FIG. 2 is an enlarged fragmentary front elevation of the control unit of FIG. 1, showing further details thereof;

FIG. 3 is an overhead plan view of the structure of FIGS. 1 and 2;

FIG. 4 is an enlarged front elevation of a single one of the dispenser components used in the control unit;

FIG. 5 is a side elevation of the dispenser component of FIG. 4; and

FIG. 6 is a schematic circuit diagram showing the electrical connections embodied in the control unit.

Description of preferred embodiment The basic physical appearance of the washer unit 10 of the invention is best seen in FIG. 1. The unit 10 includes an outer cabinet 12 which in essence is a rectangular enclosure of sheet material. This cabinet has a horizontal partition or divider 14 (FIGS. 1 and 2) which separates it into an upper and a lower portion and which provides a base for mounting some of the operative components of the unit, including an electrical water pump 16 having a main output pipe 80 which feeds into the washer unit output conduit 82 (FIGS. 1, 2, and 3) and a solenoid-actuated dump valve apparatus 18. The cabinet 12 has a rectangularly recessed area (FIG. 1) communicating with its front side 12a, with the side and rear walls of this recess being defined by a generally U-shaped vertically oriented sheet member 20 which extends upward from the horizontal divider 14. Vertical wall 20 provides a mount for other operative components of the washing unit. As best seen in FIGS. 2 and 3, these include a timer device or programmer 22, a pair of dispenser components 24 and 26, and a liquid level-detecting sensor 28, all of which operate electrically and are interconnected with the timer 22, in a manner to be seen in FIG. 6.

The portion of the cabinet 12 which is below the horizontal divider 14 encloses a tank or reservoir 32 (FIG. 2), defined by lateral and bottom sides of sheet construction. A centrally located return inlet 34 (FIGS. 1 and 2) communicates through the front face 12a of the cabinet and into the interior of the reservoir, and an outlet 36 is formed in one lateral wall of the reservoir. It is to be observed that the bottom or floor of the reservoir slopes continuously toward this outlet from the opposite side, so that all the liquid in the reservoir will run toward this outlet to empty the reservoir when the dump valve 18 is actuated to open the outlet.

As FIG. 2 best illustrates, the pump 16 has an inlet conduit 38 which extends downwardly into reservoir 32 through the horizontal divider 14 and preferably terminates just above the bottom of the reservoir. A cylindrical -'air chamber 40 also extends downwardly into reservoir 32 through the divider 14. Chamber 40 is open at the bottom but is closed at its top by a plug 42, through which passes a sensing tube 44 which leads to the level sensor 28 noted previously. This level sensor is a conventional component which operates on the basis of pressure changes, and it is the function of the sensing tube 44 to couple the air pressure present within the air chamber 40 to the sensor unit 28, so that the latter may produce an electrical switching function when a predetermined pressure has been reached in the air chamber. This pressure increases as the level of liquid inside the reservoir 32 rises against the volume of air trapped in air chamber 40 to progressively compress such air; therefore, the air pressure coupled to the sensor 28 by the sensor tube 44 is directly related to the level of the liquid within the reservoir.

As seen in FIG. 3, the horizontal divider 14 has an aperture 48 therein leading into the reservoir 32, and a plurality of hoses or other such conduits pass through aperture 48 to communicate with the interior of the reservoir. A total of three such conduits pass through aperture 48. These are as follows: a conduit 50 which leads from the dispenser component 26, a conduit 52 which leads from dispenser unit 24, and a conduit 55 which leads from the interconnection of a conduit 54,

connected to the outlet 80 of p mp 16 (FIGS. .2 and and a conduit 56 which is coupled to a pair of Y-connected fresh water inlets 58 and 60, by which the washer unit is coupled to sources of hot and cold water, respectively. As best seen in FIGS. 1 and 2, the fresh water inlets 58 and 60 are mounted in an upright position by a plate 62 secured to the rear side 12b of the cabinet 12. The flow through the two inlets 58 and 60 is combined through a Y-type coupling leading into the aforementioned conduit 56, and each respective inlet has a solenoid-operated valve 63 and 64 providing a flow-control gate means for controlling the amount of water which is admitted. The incoming water from inlets 58 and 60 present in conduit 56 is primarily directed into reservoir 7 32 through conduit 55; however, the interconnection of conduits 56, 55, and 54 serves to direct some of the inlet water to the outlet side of pump 16, so that the pump will be certain to be primed when it is subsequently energized and driven. For this purpose it may be desirable to include a check valve (not specifically shown) at the junction of conduits 54, 55, and 56, i.e., to maintain a head of water on the pump outlet. As will -be stated more fully hereinafter, control signals for operating the solenoid valves 63 and 64 are produced by the timer 22 and the sensor 28, at times and under conditions conforming to the program of sequenced Wash cycles controlled thereby.

As may be seen in FIG. 3, the dispenser components 24 and 26 have a second conduit 66 and 74, respectively, coupled thereto, in addition to the conduits 50 and 52 mentioned above which lead into the reservoir 32 through aperture 48 in divider panel 14. Conduits 66 and 74 are water supply or inlet conduits, which communicate with their respective dispenser components through solenoid operated valves 68 and 76, respectively. Supply conduit '66 is coupled through its solenoid valve 68 to a conduit 70 which leads to a T-type fitting 72 (FIG. 2) connected to the main outlet pipe of the pump 16. In a similar manner, conduit 74 for dispenser component 26 is coupled through its solenoid valve 76 to a conduit 78 leading to the other side of T fitting 72 at the pump outlet.

The dump valve apparatus 18 mentioned previously is best seen in FIGS. 2 and 3. This apparatus includes a pivot arm 84, which carries a closure valve member 86 in the form of a resilient pad at its lowermost end for closing off the outlet 36 of the reservoir. Pivot arm 84 is normally held in a position closing outlet 36 by a relatively stiff tension spring 88 anchored at one end to the horizontal divider 14. However, upon actuation of a solenoid 90, the armature 92 of the solenoid is pulled toward the solenoid, thereby pivoting arm 84 about its pivotal axis, designated 92, in a counterclockwise direction, thereby swinging the resilient pad or stopper element 86 away from the reservoir outlet 36, allowing the reservoir to empty.

The dispenser means referred to herein is comprised of the two dispenser components 24 and 26 noted previously. These components are preferably identical, and details of component 24 are shown in FIGS. 4 and 5 as being exemplary of either such dispenser. As will be seen in these figures, dispenser unit 24 has a container 94, preferably a glass or other type jar, which is removably held to a mounting structure 96. This is accomplished by a U-shaped bail 98 having an eccentrically rotatable camming element 100 mounted at the bottom thereof. Cam element 100 has a fiat spot, shown at its top in these two figures, for indexing against the bottom of the container 94 and holding the latter upwardly in place, and the cam element has a handle 102 by which it may be eccentrically rotated so that the aforesaid flat area is moved away from the bottom of the container. The eccentric rotation of the cam allows the container to move downward- 1y away from its mounting structure, to permit removal of the container. This is for the purpose of refilling the container, which is open at its top.

The U-shaped bail 98 of the dispenser component is sec red at its top to the horizontal portion of an angular mounting bracket 104, to which the mounting structure 96 is firmly afiixed, and by which the entire dispenser component is secured to the vertical wall 20 at the rear of the recess in the front wall 12a of the cabinet (FIGS. 1 and 3). The mounting structure 96 provides what is in essence a cover 106 for the container 94, into which the top of the container is insertable, preferably against a gasket or the like which prevents leakage between the jar and the cover. An inlet tube 108 extends downwardly from the bottom of cover 106 into the interior of the container 94. Inlet tube 108 is attached to the cover and communicates with a passage 110 within the cover which leads to a fitting 112, by which the inlet conduit 66 noted previously is coupled to the dispenser component.

From the foregoing it will be apparent that upon actuation of control solenoid 68, liquid will pass from conduit 70 through conduit 66, coupling 112, passage 110, and inlet tube 108 into the interior of the container 94. A second passage 114 in cover 106 opens downwardly through the bottom of the cover and communicates with the open top of the container, to thereby provide an outlet port for it. Passage 114 communicates with an outlet fitting 116 by which the outlet conduit 52 noted previously and seen in FIG. 3 is attached to the dispenser component. It is to be noted that the inlet tube 108 is located centrally of the container 94 and oriented to point downwardly, directly at the bottom of the container. In this manner, liquid entering the container through tube 108 under pressure from pump 16 will impinge directly against a cleaning or sanitizing agent present in the container. Further, the inlet tube 108 is preferably of a smaller diameter than the coupling 112 and the supply conduits 70 and 66 connected thereto, so that the inlet tube in effect defines a nozzle which will impart higher pressures and velocities to liquids entering the container therethrough. This arrangement serves to direct the entering liquid against hthe cleaning or sanitizing agent in a hard and fast stream which thoroughly agitates the agent and quickly mixes it into the entering liquid.

As has been noted, the outlet port for the container provided by passage 114 in the cover 106 is positioned considerably above the end of inlet tube 108 and also above the level of any agent which may be present in the container. Consequently, it will be apparent that such agent must be completely flooded by the incoming liquid before it will be discharged out of passage 114 and coupling 116, through which it is carried by the force of the liquid entering the container through the inlet tube. Because of the interconnection between coupling 116 and conduit 52 noted previously, such intermixed liquid and cleaning agent is carried directly into the reservoir 32, where it is further mixed with liquid present in the latter. This arrangement has been found to be very advantageous, since even granular cleaning agents will be readily dissolved by the turbulence of the liquid forced into and through the container, resulting in the fast and complete removal of the cleaning agent from the container.

The preferred circuit by which the timer 22 operates the various controlled components of the present washer unit to cause the desired sequence of events is illustrated in FIG. 6. A first power supply portion 116 of this circuit, shown at the top of the schematic, is provided for integrating a control portion 118 of this circuit, shown at the bottom of this figure, with the existing conventional agitator motor circuit 120, with which essentially all bulk tanks come equipped.

The existing agitator motor control circuit 120 has a pair of leads 122 and 124 by which it is connected to a source of AC power, and these leads normally are connected to the existing motor protection means and thence to the agitator motor itself, typically through an on-otf switch which is not shown. In accordance with the present washer unit, leads 122 and 124 are interconnected with extension leads 122a and 12411, respectively, forming a part of circuit portion 116. Also, lead 123 in the existing agitator motor control circuit 120, which normally is interconnected with power input lead 122 to Operate the agitator motor, is disconnected from lead 122 and brought out of the existing control circuit to circuit portion 116, where it is connected between a first set of normally open relay contacts labeled 1CR-1 and a second set of normally closed relay contacts labeled lCR-2. A power plug 126 is interconnected by leads 222 and 224 to circuit portion 116, with lead 222 being connected to the remaining side of the aforementioned relay contacts 1CR-1 and lead 224 being interconnected with lead extension 124a of the existing motor control circuit 120, so that the existing and the new power supply circuits have a common ground. Power lead extension 122a of the existing motor control circuit 120 connects to the remaining side of relay contacts 1CR2, noted above.

The remainder of circuit portion 116 of the present unit is comprised of a pair of parallel circuit branches 128 and 130. These extend between a power lead extension 2220, interconnected with power lead 222 from plug 126 at one side of relay contacts 1CR-1, and lead extension 124a, which functions as the common or ground for the circuit. Circuit branch 128 includes a series-connected push-button switch S-1 and the control winding 1CR of the aforementioned relay, while circuit branch 130 includes a third set of relay contacts 1CR-3 (normally open) which is connected in series with a pilot lamp 132. It will be noted that a pair of conductors and 142 extend between circuit portions 116 and 118 through a grounded cable 144. Conductor 140 is connected between switch S-1 and relay winding 1CR in branch 128 of circuit portion 116, while conductor 142 is connected to branch 130 of circuit portion 116 between relay contacts lCR-3 and the pilot lamp 132. Conductors 140 and 142 are interconnected within circuit portion 118 by a conductor 141 thereof, which serves as a main power buss for circuit 118, together with an extension 141a of conductor 141. These conductors will thus be seen to form a loop which serves to maintain the energization of relay 1CR after push-button switch S-1 has been re leased, in a manner to be seen subsequently.

In its general nature, circuit portion 118 is generally similar to many control circuits, in that it has a positive voltage or power, i.e., buss conductor 141, a ground or common buss (conductor 124a), and a plurality of switching circuit branches 150, 152, 154, 156, 158, 160, 162, and 164, which are connected between conductors 141 and 124a. The timer 22 found in circuit 118 is a conventionally known device having an electric motor (seen in circuit branch and designated 170), which upon actuation drives a plurality of cams to provide electrical switching functions. In circuit 118, these cam switches are appropriately labeled by a general designation cam switches on timer, and each such switch is specifically labeled cam #2, cam #3," etc.

With specific reference to circuit portion 118, the branch 150 thereof includes cam switch #2, a push-button switch S2 (which is located on the timer 22) and the aforementioned timer motor 170. Circuit branch 152 contains cam switch #6 connected in series with a normally open set of contacts 2CR1 of a second control relay, together with solenoid 64 which controls the supply of water from inlet 60 seen in FIGS. 1 and 2. Circuit branch 154 contains cam #5, an overload protection unit 172, and the motor of pump 16, all connected in series. Circuit branch 156 contains cam switch #3 and the solenoid 68 which controls the operation of dispenser component 24. Circuit branch 158, like branch 156, contains cam switch #3 and the solenoid 90 forming a part of the dump valve apparatus 18. Circuit branch 160 contains cam switch #1, the electrical switch contacts from sensor unit 28, and the control winding of the aforementioned second control relay ZCR. Circuit branch 162 contains cam switch #4, a set of normally open relay contacts 2CR-2, and the solenoid 63 which controls the hot water supply inlet 58. Cir- 7 cuit branch 164, like branch 162, contains cam switch #4 and the solenoid 76 which controls the operation of dispenser component 26.

Operation Until actuation of switch Sl, both circuit portions 116 and 118 are inactive, and the connection of the existing power leads 122 and 124 to line power merely serves to operate the agitator motor in the usual manner, since a path is closed through conductor 122, conductor 122a, relay contacts 1CR2, and connector 123. However, when switch S-1 is closed, the control relay lCR of branch 128 is energized, thereby opening relay contacts lCR-Z and thus opening the aforesaid circuit path to the agitator motor. Nonetheless, the motor remains energized, since relay ICR has closed its contacts ICR-l and a circuit path is now provided from plug 126 through power lead 222, through relay contacts 1CR-1, now closed, and through conductor 123. At the same time, relay contacts 1CR-3 in branch 130 are also closed, thereby energizing the pilot light 132, which indicates that the washer unit has been energized.

While switch S1 is actuated only momentarily, the actuation thereof and the resultant closing of branch 130 in circuit 116 allows current to flow through conductor 142 to branch 150 of circuit portion 118. In order for the washer unit to begin its operative cycle, the timer 22 must be set at a start position in which its cam #2 closes the switch controlledthereby. Also, the switch S2 on the timer must be closed. Under these conditions branch 150 is closed, and the current in conductor 142 flows through branch 150 to energize the timer motor 170 and also to flow through conductor 141a to buss conductor 141. From the latter a path exists through part of branch 160 and conductor 140 back to branch 128 of the upper circuit portion 116. This supplies power to relay 1CR to maintain it in an energized condition even though the pushbutton switch Sl is then released. It will be recognized that this provides a holding circuit or loop for relay lCR which includes its own contacts 1CR-3, and that relay 1CR can thus be de-energized only by opening one of the other switching elements in this loop. Upon inspection it will be seen that such can only be cam switch #2 or else switch S2 of the timer 22, which thus is enabled to automatically end the washing sequence controlled thereby.

Operation of circuit branch 118 is based on the operation of the timer unit 22, which in essence comprises the steady or sequential opening and closing of the various cam switches on the timer and the resultant opening and closing of circuit branches 150 through 164 inclusive. This produces a sequential operation of the washer unit which is as follows. First, a pre-rinse occurs of a duration of approximately five minutes and consisting of pure water of moderate temperatures. This is produced by closing circuit branches 150, 152, 154, 160, and 162. Circuit branch 150 is closed in the manner previously stated, i.e., by manually operating the timer 22 by setting it at its start position, in which cam switch #2 is closed, and by actuating its switch S2, which ideally is actuated by pushing or pulling the operating knob itself, in a familiar manner. At this time, the timer motor has caused cam switch #1 in circuit branch 160, to close, and inasmuch as no water is then in the reservoir 32, the water level switch 28 is in a closed condition. Branch 160 thus energizes relay winding 2CR (considered to be a part of the overall programmer or timer means of the control), with the resultant closing of relay contacts 2CR-1 in circuit branch 152 and 2CR-2 in circuit branch 162. The timer motor 170 also closes cam switch #6 in circuit branch 152 in sequence, actuating the solenoid 64 which controls water inlet 60 and causing cold water to be admitted into the reservoir. Further, cam switch #4 is also closed to close circuit branch 162, actuating solenoid 63 which controls the hot water inlet 58, whereupon hot water is mixed with the cold Water and both enter the reservoir 32 to 8 produce a quantity of water therein of moderate temperature.

When the reservoir becomes filled to the desired level, the water level switch 28 automatically opens upon detecting the predetermined level. This opens circuit branch 160 and de-energizes control relay 2CR, which in turn opens circuit branches 152 and 162 and thereby stops the supply of water flowing into the reservoir. At a predetermined time (preferably shortly after the filling of the reservoir), cam switch #5 is closed by the timer 22, thereby energizing the water pump 16, with the result that water from the reservoir is pumped from the pump inlet 38 (FIG. 2) through the pump 16, out of the pump outlet 89 and the output conduit 82 to the spray means in the bulk tank connected thereto. Consequently, the tank is rinsed with the clear water of moderate temperature from the reservoir for a desired interval programmed into the timer operation, until cam switch #5 is automatically opened to stop the pumping operation and cam switch #3 is simultaneously closed, to close circuit branch 158 and thereby energize the dump valve solenoid 90, whereupon the rinse water is drained from the reservoir.

Next, a washing cycle of hot soapy water occurs for a duration of approximately fifteen minutes. In accomplishing this, the timer once again closes cam switch #1 in branch 160 and, since the reservoir has been emptied, the water level switch 28 completes the circuit in this branch to energize relay 2CR and close the contacts thereof in circuit branches 152 and 162, as before. However, at this time cam switch #6 in branch 152 is open, so that the cold water solenoid 64 is not energized. On the other hand, cam switch #4 is closed at this time to complete a path through branch 162, thereby energizing the hot water solenoid 63 and sending hot water into the reservoir. Once again, when the water level switch 28 senses the proper quantity of liquid within the reservoir it opens to de-energize relay 2CR and stop the filling operation. Cam switch #5 then operates to close circuit branch 154 and energize the pump 16, thereby sending hot water from the reservoir through output conduit 82 and to the bulk tank.

At this point, cam switch #3 operates to close a path through branch 156 and energize solenoid 68, thereby diverting part of the hot water being pumped out of the pump outlet 82 into conduits 70 and 66 to the dispenser component 24, which is then holding a desired quantity of soap. This flushes the soap out of this dispenser component and through conduit 52 into the reservoir, Where the soap is thoroughly dissolved into and mixed with hot water already in the reservoir. This is accomplished in a very short time, and consequently cam #3 may be programmed to open circuit branch 156 after a relatively short interval. Circuit branch 154, on the other hand, is maintained closed for the fifteen minute interval, during which the hot soapy water is pumped to the bulk tank out of the pump output 82. At the end of this period, cam switch #3 closes circuit branch 158 to energize the drain solenoid and empty the reservoir of the hot soapy water, and cam switch #5 is simultaneously opened to stop the operation of pump 16.

The next sequential operation comprises a pair of separate cold water rinses for cleansing the bulk tank of any soap solution adhering to its walls. These rinses are accomplished by circuit branches 160 and 152; i.e., cam switch #1 and the Water level switch 28 together close circuit branch 160 in the manner stated previously to energize relay 2CR, and cam switch #6 operates to close circuit branch 152 in conjunction with the then-closed relay contacts 2CR1, thereby energizing cold water solenoid 64 to send cold water into the reservoir 32. When the reservoir has filled, the water level switch 28 opens circuit branch 160 to de-energize relay ZCR and stop the filling operation just noted. At this time, cam switch #5 once again closes to complete a path through circuit branch 154 and energize the pump 16, which then pumps the cold water out of the reservoir and to the bulk tank from the pump output. At the end of the first three minute interval cam switch opens to open branch 154 and stop the pump 16, and cam switch #3 closes circuit branch 158 to energize the drain solenoid 90, whereupon the first charge of cold water is emptied from the reservoir. The foregoing cycle is then repeated once again, to provide the aforementioned second rinse of clear cold water.

The final operation in the washing sequence is a five minute acid rinse which sterilizes the bulk tank, neutralizes any slight soap film which may have been left in it after the dual rinse, and eliminates any water spotting of the interior due to minerals in the water which is used. This acid rinse is accomplished first by the operation of cam switch #1 and the water level switch 28 which act to close circuit branch 160, and by cam switch #6 and circuit branch 152, by which the cold water solenoid 64 is energizied to fill the reservoir with cold water. Cam switch #5 then closes circuit branch 154 once again to start the water pump 16, and at the same time cam switch #4 closes circuit branch 164 to energize solenoid 76. This directs cold water from the pump output 80 to dispenser component 26, which contains an amount of a desired sterilizing acid, normally an acetic acid. In the same manner as the soap discharged from dispenser 24, the acid from dispenser 26 is flushed into the reservoir where it is thoroughly intermixed with the cold water already therein and pumped out of the washer unit outlet 82 to the bulk tank. Once again, after the desired interval has passed, cam switch #5 opens branch 154 to stop the pump 16 and cam switch #3 closes circuit branch 158 to energize the drain solenoid 90 and drain the acid bath from the reservoir.

At this time, the timer 22 finally opens cam switch #2, which has been closed throughout all of the foregoing sequence. When cam switch #2 is opened, it opens circuit branch 150. This deenergizes the timer motor 170 and also removes the power previously coupled by conductor 141a to the power conductor or buss 141 of the circuit portion 118, whereupon power is removed from branch 160 and conductor 140 which leads back up to circuit portion 116 and which has been holding the coil of relay 1CR in an energized condition. When power is removed from conductor 140 in this manner, relay 1CR is deenergized and relay contacts 1CR-3 are opened, thereby opening branch 130 of circuit 116. This extinguishes the pilot light 132 and removes the power from conductor 142, at which point the entire circuit has been deenergized and all operation of the washer unit ceases.

It should be expressly noted that the washer unit of the invention may be operated to perform only the sanitizing cycle just described, after which the timer will automatically shut the unit down in the same manner (i.e., by opening cam switch #2). This abbreviated sequence is particularly advantageous where the bulk tank has been washed and sterilized at a time in the past, but an interval has since occurred during which the tank was not used. Under these circumstances, the law requires that the tank be sterilized once again (although not necessarily rewashed) before being put into use, and it will be apparent that the abbreviated sequence noted is an ideal way to accomplish this. All that need be done to initiate this abbreviated sequence is to place the desired sanitizing agent in the container of dispenser component 26, manually advance the timer a predetermined extent (preferably to a positive stop or at least to an appropriate indicia) with its switch 8-2 in the off position, close timer switch S-2, and then push switch S-l, whereupon the brief sanitizing cycle will be automatically run, following which the washer unit will automatically shut off.

During all of the foregoing operations, the various washing and rinsing solutions supplied to the bulk tank are continuously returned, preferably by gravity, to the reservoir 32 through its return inlet 34, so that each of the sequenced cleaning operations is continuous or circulating in nature. Also, if at any time in any such sequential operation the level of the washing liquid within the reservoir 32 decreases beyond the predetermined minimum amount, the water level switch 28 will once again automatically close, thereby initiating a refilling of the reservoir to the desired level with water from the inlet of the same character already present in the reservoir, i.e., hot water, cold water, or a mixture of each, as determined by the particular cam switch then closed by the timer unit. This will be recognized as being a very desirable feature, inasmuch as the bulk tanks to which the invention is addressed are not tightly sealed at their top and consequently a portion of the water sprayed inside the tanks in the various cleaning operations is quite likely to escape the tank and thereby steadily diminish the amount of water present in the reservoir. Thus, in accordance with the present washer unit, it is contemplated that the reservoir vvill periodically be replenished to maintain the liquid therein at the desired level.

The many advantages provided by the present invention not specifically enumerated or stressed hereinabove will likely be immediately grasped by those having skill in the pertinent arts. It is entirely conceivable that upon examining the foregoing disclosure, those skilled in the are may device embodiments of the invention which differ somewhat from the embodiment shown and described herein, or may make various changes in structural details to the present embodiment. Consequently, all such changed embodiments or variations in structure as utilize the concepts of the invention and clearly incorporate the spirit thereof are to be considered as within the scope of the claims appended herebelow, unless these claims by their language specifically state otherwise.

We claim:

1. A source apparatus for providing a controlled sequence of washing liquid for cleaning bulk storage tanks and the like, said apparatus comprising in combination: a cabinet means, including a reservoir for holding a pre determined quantity of liquid; a source of liquid; means coupling said source to said reservoir to transfer liquid thereinto, said coupling means including liquid flow gating means for starting and stopping the flow of liquid to said reservoir; an outlet conduit for coupling said reservoir to a desired bulk tank or the like and transferring liquid from the former to the latter; a return conduit for transferring liquid from such bulk tank back to said reservoir; pump means for circulating liquid between said reservoir and said bulk tank through said outlet and return conduits; and dispenser means for holding desired cleaning and sterilizing agents and dispensing the same into said liquid in response to a command signal, such that said liquid when so circulated may contain such agents in dissolved form.

2. The apparatus recited in claim 1, further including means for maintaining said predetermined quantity of liquid in said reservoir.

3. The apparatus recited in claim 2, wherein said means for maintaining said predetermined quantity of liquid includes at least one sensing component for detecting the actual amount of liquid within said reservoir and controlling said flow gating means in response to said detected amount to provide additional liquid from said source if such amount is less than said predetermined quantity.

4. The apparatus recited in claim 3, wherein said sensing component is of a type which monitors the height of the liquid within said reservoir.

5. The apparatus recited in claim 1, wherein said dispenser means is coupled to said reservoir to dispense said agents thereinto.

6. The apparatus recited in claim 5, wherein said dispenser means is coupled to said reservoir by conduit means interconnected with said source, such that said agents are carried into said reservoir by liquid from said source.

7. The apparatus recited in claim 1, wherein said dispenser means includes at least two independent dispenser components, each having a control element responsive to a separate command signal, and wherein said apparatus further includes a timer device for providing separate time-spaced command signals to said control elements, such that said dispenser components dispense their respective agents in a desired sequence.

8. The apparatus recited in claim 7, wherein said liquid flow gating means is also responsive to command signals in starting and stopping the flow of said liquid, and wherein said timer device is arranged to provide such command signals as a part of said sequence.

9. The apparatus recited in claim 8, wherein said apparatus further includes a dump valve means for emptying said reservoir of liquid in response to command signals, and wherein said timer device is arranged to provide such command signals as a part of said sequence.

10. The apparatus recited in claim 9, wherein said timer device is arranged to supply command signals to said dump valve means, said flow gating means and said dispenser components in a fixed sequence wherein said reservoir is emptied and refilled with fresh liquid from said source before either of said dispenser components is actuated to dispense its agent.

11. The apparatus recited in claim 10, wherein said timer device is arranged to provide command signals to said dump valve means to empty said reservoir a desired interval after operation of the second dispenser component and to thereafter end said sequence by turning itself off.

12. The apparatus recited in claim 11, wherein said timer device is resettable to provide an abbreviated sequence in which only a single dispenser component is actuated to dispense its agent prior to ending such sequence by said timer turning itself oflf.

13. The apparatus recited in claim 11, wherein said dispenser components are each coupled to said reservoir to dispense said agents thereinto.

14. The apparatus recited in claim 13, wherein said dispenser components are each coupled to said reservoir by conduit means interconnected with said source, such that said agents are carried into said reservoir by liquid from said source.

15. The apparatus recited in claim 14, further including means for maintaining said predetermined quantity of liquid in said reservoir.

16. The apparatus recited in claim 15, wherein said means for maintaining said predetermined quantity of liquid includes at least one sensing component for detecting the actual amount of liquid within said reservoir and controlling said flow gating means in response to said detected amount to provide additional liquid from said source if such amount is less than said predetermined quantity.

17. The apparatus recited in claim 16, wherein at least one of said dispenser components comprises a container for said agent, an inlet tube communicating with the interior of said container for transferring liquid thereinto, and an outlet port structure communicating with the interior of said container and coupled to said reservoir; said outlet located at a level above that of the agent within said container, such that said agent must be at least partially flooded by liquid from said inlet before either the agent or liquid can pass out of the outlet and into the reservoir.

18. The apparatus recited in claim 17, wherein said outlet is located substantially above the level of said agent, such that the latter must be substantially flooded by said liquid before either the agent or liquid can pass out of the outlet and into the reservoir.

19. The apparatus recited in claim 18, wherein said inlet tube extends into said container and is oriented to direct liquid passing through such tube directly against said agent.

20. The apparatus recited in claim 19, wherein said inlet tube has portions defining a nozzle of at least slightly constricted diameter, such that liquid discharged from such nozzle is impinged against said agent under increased pressure.

References Cited UNITED STATES PATENTS 1,592,126 7/1926 Paige 233 11 2,407,765 9/ 1946 Palmer 222-- 2,458,230 1/1949 Warcup 222148 X FOREIGN PATENTS 550,410 9/ 1956 Belgium.

ROBERT B. REEVES, Primary Examiner.

a H. S. LANE, Assistant Examiner.

US. Cl. X.R. 

